[UNSTABLE][PATCH v2] UBUNTU: [Packaging] Build and include GDB Python scripts into debug packages

[Matthias Klose]

On 5/17/21 9:37 PM, Dimitri John Ledkov wrote:
> Hi,
> 
> On Mon, May 17, 2021 at 7:50 PM Krzysztof Kozlowski
> <krzysztof.kozlowski at canonical.com> wrote:
>>
>> The kernel comes with useful GDB debugging scripts/commands (enabled
>> with CONFIG_GDB_SCRIPTS), however these are built either with "all" make
>> target or with "scripts_gdb".  Build these in
>> "$(stampdir)/stamp-build-%" target and package in "install-%" under
>> /usr/lib/debug/share.
>>
> 
> I'm still not too sure about this location. Where did it come from?
> 
> Normally, when running under gdb it has autoload functionality of
> loading auxiliary scripts.
> 
> Ie. python3.9-gdb for the interpreter ships the below
> /usr/share/gdb/auto-load/usr/bin/python3.9-dbg-gdb.py
> 
> Would it not make more sense to ship the gdb kernel scripts under like
> 
> /usr/share/gdb/auto-load/boot/vmlinuz-X.Y.Z-gdb.py ? Or do they at all
> cannot work with gdb auto-load functionality? Can we store them
> somewhere by build-id note (if that is at all helpful)?
> 
> Where do other distributions ship these gdb scripts? Cause i have not
> seen /usr/lib/debug/share before.

if you don't configure gdb explicitly with

  --with-auto-load-dir=PATH
                          directories from which to load auto-loaded scripts
                          [$debugdir:$datadir/auto-load]

/usr/share/gdb/auto-load would be the default.  So
/usr/share/gdb/auto-load/boot/vmlinuz-X.Y.Z-gdb.py sounds sensible.  However I
didn't check if gdb is smart enough to do the auto-loading for non ELF binaries.

Basing the lookup on build id's might be possible, would need an upstream patch.
However you can't easily determine anymore which autoload capbilities you have
installed. Having a real name in the auto-load directory is much more descriptive.

Matthias

>> BugLink: https://bugs.launchpad.net/bugs/1928715
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski at canonical.com>
>>
>> ---
>>
>> Changes since v1 (RFC):
>> 1. Add a comment inside .mk.
>> 2. More tests.
>> ---
>>  debian/rules.d/2-binary-arch.mk | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/debian/rules.d/2-binary-arch.mk b/debian/rules.d/2-binary-arch.mk
>> index 0b008df5a853..d297dc84ff48 100644
>> --- a/debian/rules.d/2-binary-arch.mk
>> +++ b/debian/rules.d/2-binary-arch.mk
>> @@ -49,6 +49,13 @@ $(stampdir)/stamp-build-%: $(stampdir)/stamp-prepare-%
>>         @echo Debug: $@ build_image $(build_image) bldimg $(bldimg)
>>         $(build_cd) $(kmake) $(build_O) $(conc_level) $(bldimg) modules $(if $(filter true,$(do_dtbs)),dtbs)
>>
>> +ifneq ($(skipdbg),true)
>> +       # The target scripts_gdb is part of "all", so we need to call it manually
>> +       if grep -q CONFIG_GDB_SCRIPTS=y $(builddir)/build-$*/.config; then \
>> +               $(build_cd) $(kmake) $(build_O) $(conc_level) scripts_gdb ; \
>> +       fi
>> +endif
>> +
>>         @touch $@
>>
>>  define build_dkms_sign =
>> @@ -295,6 +302,12 @@ ifneq ($(skipdbg),true)
>>         # Debug image is simple
>>         install -m644 -D $(builddir)/build-$*/vmlinux \
>>                 $(dbgpkgdir)/usr/lib/debug/boot/vmlinux-$(abi_release)-$*
>> +       if [ -d $(builddir)/build-$*/scripts/gdb/linux ]; then \
>> +               install -m644 -D $(builddir)/build-$*/vmlinux-gdb.py \
>> +                       $(dbgpkgdir)/usr/lib/debug/share/$(abi_release)-$*/vmlinux-gdb.py; \
>> +               install -m644 -D $(builddir)/build-$*/scripts/gdb/linux/* \
>> +                       --target-directory=$(dbgpkgdir)/usr/lib/debug/share/$(abi_release)-$*/scripts/gdb/linux; \
>> +       fi
>>         $(build_cd) $(kmake) $(build_O) modules_install $(vdso) \
>>                 INSTALL_MOD_PATH=$(dbgpkgdir)/usr/lib/debug
>>         # Add .gnu_debuglink sections only after all/DKMS modules are built.
>> --
>> 2.27.0
>>
>>
>> --
>> kernel-team mailing list
>> kernel-team at lists.ubuntu.com
>> https://lists.ubuntu.com/mailman/listinfo/kernel-team
> 
> 
>